Hour-striking time mechanism.



G. F. FRIBERG.

HOUR STRIKING TIME MECHANISM.

APPLICATION FILED 11m18.191s.

Patented Feb. 13,` 1917.

CIK

GUSTAF F. FRIBERG, OF CHICAGO, ILLINOIS.

HOUR-STRIKING TIME MECHANISM.

Specication of Letters Patent.

Patented Feb. 13, 1917.

Application led May 18,1916. Serial No. 98,293.

To all whom t may concern:

Be it known that I, GUSTAF F. FRIBERG, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in Hour-Striking TimeMechanisms, of which the following.

is a specification. n

' This invention relates to hour striking mechanisms for clocks or timepieces. Its general object is to do away with the strike train of gearsand its separate winding spring and let the going train, or timemechanism, automatically, during each hour, provide sufficient power forthe number of hammer blows required to strike one hours time. This isaccomplished in the present invention by means of a lever escapementunder constant spring tension set by the time mechanism during vthe halfhour preceding each striking to escape the same number of teeth thatblows are to be struck.

The invention consists in the novel construction, combination, andarrangement of parts, all as hereinafter described in detail,illustrated in the accompanying drawing and incorporated in the appendedclaim.

In the drawing-n Figure 1 is a front view of the going train of anOrdinar clock, the parts which are old and well own being shown bydotted lines and my improvements in full lines.l

Fig. 2 is a transverse section taken substantially on line 2-2 of Fig. 1and omitting, for the sake of greater clearness, some of the detailsshown in Fig. 1.

Fig. 3 is a view of the striking mechanism alone being set preparatoryto striking the hour.

In Fig. 1 the steps formed on the involute curve of the usual snail -13-which determines the number of blows and which is fast on the arbor 14+of the hour hand -15- (Fig. 2), are labeled 1 to 12, inclusive. Myinvention is illustrated in connection with a common form of small alarmclock the bearing plates of which are supported on lugs 14 on a castring 15 to which 'two of the feet 'or legs 416- are attached. Only thefront bearing plate -17- attached to said cast ring, is shown,

screws 18 indicating the connections for' the rear plate, between whichand the front plate 17 that portion of the usual time mechanism withwhich this invention is not intimately concerned, is placed. As shown inFig. 2 my improvement is arranged between the front bearing plate 17 andthe hands of the clock, 19 representing the minute hand.

20 is the axis of the time mechanism driving spring, and of the mainwheel, and its driving ratchet. The main wheel drives the center pinionwhich rotates on the minute hand arbor. The vcenter' wheel drives thethird pinion and third wheel, the second pinion being on the same axisas the irst pinion but fast on the arbor 21 and indicated by the numeral22 in Fig. 2. The third wheel drives the fourth pinion and fourth wheel,

4the latter. drives the escapement pinion, and

the escapement wheel swings the balance wheel- 23 in Fig. 1. Only theback gearing from the pinion 22, which drives the hour hand 15, is shownin Fig. 1, namely, the wheel 24 driven by pinion 22 and carrying apinion 25 which rotates the hour wheel 26 that is loosely mounted on thearbor 2l. The power for setting my striking mechanism is taken from thewheel 24 through a pinion 27 which pinion is the only toothed wheeladded to the trains of gears of theordinary clock.

Referring, now, to the improved houx` striking mechanism, an escapementsegment 28 with teeth 29 engages pallets 30 and 31 on a member 32 thatis pivoted on a stud 33 on'the lower end of an arm 34 pivoted af 35 tothe bearing plate 17 and placed under tension of a spring 36 which tendsto force the pallets towardr and in engagement with the teeth 29. Thespring 36 is secured at 37 to the bearing plate in which is a stop pin38 that supports the spring against turning backward on itsfasteningscrew or pin 37. The segment 28 is on an arm 39 vwhich ispivoted on a stud 40 held in the bearing plate 17. The arm 39 has anintermediate U-shaped portion 41 which carries the arm 39 clear ofinterference with the secondhand and its arbor -42- and underneath thearbors 21 and 14 to give it unrestricted clearance for its downwardmovement when set to strike as in Fig. 3. The arm 39, 41 is really apart of a bell crank lever, the other arm of which is a stud 43 on a hub44 that is mounted on the pivot 40. The arm 43 of this bell crank leveris held under tension of a spring 45 one end of which is attached to thearm 43 and the other end attached to a stud 46 on the ring 15. Thisspring tension holds the escapement normally raised against a stud 47 onthe lug 14 and assists in actuating it after being set in operativeposition. The escapement segment is set, or lowered into operativeposition against the tension of the spring 45, by means of a bell cranklever having a rigid arm 4S and a flexible arm 49 that are pivoted at 50on the plate 17. rlhe flexible arm 49 is a comparatively rigid spring tothe free end of which is pivoted at 51 a lighteiI and more flexiblespring 52 which connects the arm 49 with the U 41 at 53. rl'he lever 48,49 and 52 is lowered or swung into operative position by means of ashort arm or horizontal stud 54 on the arm 55 which extends from the hub56 of the pinion 27. The latter is of the same size as the second pinion22 and is therefore rotated at the same speed, that is, synchronouslywith the minute hand. n third bell crank lever with a power arm 57 and aload arm 5S is pivoted on the bearing plate 17 and serves to hold thepallets 30 and 31 out of engagement with the teeth 29 between thestriking periods. T his is accomplished by means of a circular disk 60that is fast on the arbor 14 between the pinion and the wheel 2G .andengages a pin 61 which projects laterally from the end of lever arm 57and rests on the edge of the disk. ln the disk 60 is a recess G2, or camdip, into which the pin (3l is admitted immediately before each strikotakes place and in which it is held, by suitable elongation of the slotG2, until the striking is over. ylhe bell clapper or hammer WG3- is on awire arm G4 which is an upward continuation of the member 32 carryingthe pallets, and is balanced by a weight G5 on a similar arm G6 thatextends downwardlyT from the member' 32. At the moment when the pin 61drops into the depression G2 to permit the lever arm 5S to yield itsresistancev to the bracket 34 under pressure of the spring 3G, theengagement of the pallets with the teeth causes a quiver in the balancedhammer causing it to make a slight tap on the bell 67- as a warning thatthe clock is about to strike, thus, at night giving a sleepy person timeto prepare for counting the strokes. lmmediately thereafter, as shown inF ig. 3, the lever 55 is released from engagement with the lever arm 4Sand the pull of the spring 45 upon the toothed rack/S causes the arms 64and (Sti to swing to and fro one swing or blow for each suceessire toothdisengaged from the pallets. rlhe upward pressure on the under side ofthe pallet 30 causes the upper end ofthe member 32 to swing outwardlywhich releases the pallet 30 and swings in the pallet 31 to engage atoot-h and arrest the upward movement of the member 2S until thecounterweight resistance to the swing outward of the hammer equals themomentum and the reaction carries the hammer toward the bell to make thenext strike.

The number of teeth to be thus disengaged from the pallets, or thedistance downward that the upper end of the member 28 is moved from thestop 47 is determined by the ,snail 13 having the proper step thereinengaged by a laterally projecting lug 68 on a horn' 69 rising from thearm 39 at one end of the' U 41. A similar lug 70 projecting from theother end of the U rests on top of the spring 49, the tension of whichrelative to the anchor stud 53 for the end of the spring 52, is upward,while the pull of the spring 52 is downward, which establishesequilibrium and holds the springs and the escapement in properlyflexible relation, the lug 70 necessarily having a sliding engagementwith the spring 49.

It will be noticed that the parts added to effect the striking are verysimple elements from the manufacturers standpoint, involving but a fewcents eXtra cost and that the ,attachments are applicable to existingforms of clocks, so that non-striking clocks may be made to strike as inthe case of the simple clock illustrated in this connection. The usualstriking mechanism involves practically as much cost for spring andtrain of gears as the time mechanism, and it may therefore be said thatmy improved striking mechanism will reduce the cost of an hour strikingclock by nearly one-half to say nothing about eliminating the trouble ofwinding the eXtra spring, or bearing its winding in mind.

As explained in the foregoing the striking mechanism is cocked7 or setby the wheel 24 of the train of gears which slows down to the speed ofrotation of the hour hand the speed of the minute hand, namely, thetrain 22, 24, 25 and 26, and as the pinion 27 has the same number ofteeth as the pinion 22 the arm 55 makes its complete revolution in thesame period as does the minute hand. lnv Fig. 1 the cooking of thestriking mechanism has been commenced, the lug or short arm 54 beginningits moving engagement with the lever arm 48 at the lower end of thelatter which has been moved partly to the right as indicated by thespace between the upper end of the rack 28 and its stop pin 47. Thecooking movement of the arm 48 and its associated parts thus continuesthrough an arc of approximately a one half hours period, which imposesbut little strain upon the power of the time mechanism. Of course bysuitable curvature or curvatures of the lever arm 48 the setting orcocking of the striking mechanism may be prolonged throughout a largerpart of the hour, and 54 may represent the position of an anti-frictionroller. The

Weight of the pendulum 65 relative to the Weight of the hammer 63regulates the rapidity of the hammer blows.

I claim as my invention- The combination With a time keeping mechanism,of a pendulum balanced hourstriking hammer and pallets, a toothedsegment to engage said pallets, means for bringing the latter into andout of engagement with the teeth of said segment, means forautomatically adjusting by the clock movement the position of saidsegment, or to escape a given number of teeth, and a tension devicetending to swing said segment in one direction.

In testimony whereof I have hereunto signed my name.

GUSTAF F. FRIBERG.

Gopies of this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents, Washington, D. C.

